Hydrofluorocarbon compositions with tetrafluoroethane and cyclopropane

ABSTRACT

Refrigerant compositions include mixtures of difluoromethane and isobutane, butane, propylene or cyclopropane; pentafluoroethane and propylene or cyclopropane; 1,1,2,2-tetrafluoroethane and propane; 1,1,1,2-tetrafluoroethane and cyclopropane; 1,1,1-trifluoroethane and DME or propylene; 1,1-difluoroethane and propane, isobutane, butane or cyclopropane; fluoroethane and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane and butane, cyclopropane, DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane and butane, cyclopropane, isobutane or propane.

This is a division of application Ser. No. 08/435,108, filed on May 4,1995, now U.S. Pat. No. 5,672,293, which is a divisional of Ser. No.08/208,777, filed on Mar. 11, 1994, now U.S. Pat. No. 5,417,871 grantedMay 23, 1995.

FIELD OF THE INVENTION

This invention relates to refrigerant compositions that include ahydrofluorocarbon as a component. These compositions are also useful ascleaning agents, expansion agents for polyolefins and polyurethanes,aerosol propellants, refrigerants, heat transfer media, gaseousdielectrics, fire extinguishing agents, power cycle working fluids,polymerization media, particulate removal fluids, carrier fluids,buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as arefrigerant. Such refrigerants include dichlorodifluoromethane (CFC-12)and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds offluorinated hydrocarbon refrigerants released into the atmosphere mayadversely affect the stratospheric ozone layer. Although thisproposition has not yet been completely established, there is a movementtoward the control of the use and the production of certainchlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under aninternational agreement.

Accordingly, there is a demand for the development of refrigerants thathave a lower ozone depletion potential than existing refrigerants whilestill achieving an acceptable performance in refrigeration applications.Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCsand HCFCs since HFCs have no chlorine and therefore have zero ozonedepletion potential.

In refrigeration applications, a refrigerant is often lost duringoperation through leaks in shaft seals, hose connections, solderedjoints and broken lines. In addition, the refrigerant may be released tothe atmosphere during maintenance procedures on refrigeration equipment.If the refrigerant is not a pure component or an azeotropic orazeotrope-like composition, the refrigerant composition may change whenleaked or discharged to the atmosphere from the refrigeration equipment,which may cause the refrigerant to become flammable or to have poorrefrigeration performance.

Accordingly, it is desirable to use as a refrigerant a singlefluorinated hydrocarbon or an azeotropic or azeotrope-like compositionthat includes at least one fluorinated hydrocarbon.

Mixtures that include a fluorinated hydrocarbon may also be used as acleaning agent or solvent to clean, for example, electronic circuitboards. It is desirable that the cleaning agents be azeotropic orazeotrope-like because in vapor degreasing operations the cleaning agentis generally redistilled and reused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinatedhydrocarbon are also useful as blowing agents in the manufacture ofclosed-cell polyurethane, phenolic and thermoplastic foams, aspropellants in aerosols, as heat transfer media, gaseous dielectrics,fire extinguishing agents, power cycle working fluids such as for heatpumps, inert media for polymerization reactions, fluids for removingparticulates from metal surfaces, as carrier fluids that may be used,for example, to place a fine film of lubricant on metal parts, asbuffing abrasive agents to remove buffing abrasive compounds frompolished surfaces such as metal, as displacement drying agents forremoving water, such as from jewelry or metal parts, as resistdevelopers in conventional circuit manufacturing techniques includingchlorine-type developing agents, or as strippers for photoresists whenused with, for example, a chlorohydrocarbon such as1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of refrigerantcompositions of difluoromethane (HFC-32) and isobutane, butane,propylene or cyclopropane; pentafluoroethane (HFC-125) and propylene orcyclopropane; 1,1,2,2-tetrafluoroethane (HFC-134) and propane;1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane;1,1,1-trifluoroethane (HFC-143a) and dimethyl ether (DME) or propylene;1,1-difluoroethane (HFC-152a) and propane, isobutane, butane orcyclopropane; fluoroethane (HFC-161) and propane or cyclopropane;1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane,DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane(HFC-227ea) and butane, cyclopropane, isobutane or propane. Thesecompositions are also useful as cleaning agents, expansion agents forpolyolefins and polyurethanes, aerosol propellants, heat transfer media,gaseous dielectrics, fire extinguishing agents, power cycle workingfluids, polymerization media, particulate removal fluids, carrierfluids, buffing abrasive agents, and displacement drying agents.

Further, the invention relates to the discovery of binary azeotropic orazeotrope-like compositions comprising effective amounts ofdifluoromethane (HFC-32) and isobutane, butane, propylene orcyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane;1,1,2,2-tetrafluoroethane (HFC-134) and propane;1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane;1,1,1-trifluoroethane (HFC-143a) and propylene; 1,1-difluoroethane(HFC-152a) and propane, isobutane, butane and cyclopropane; fluoroethane(HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane,isobutane or propane to form an azeotropic or azeotrope-likecomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor pressure of liquid mixtures of HFC-32 andisobutane at 25° C.;

FIG. 2 is a graph of the vapor pressure of liquid mixtures of HFC-32 andbutane at 25° C.;

FIG. 3 is a graph of the vapor pressure of liquid mixtures of HFC-32 andpropylene at 25° C.;

FIG. 4 is a graph of the vapor pressure of liquid mixtures of HFC-32 andcyclopropane at 0° C.;

FIG. 5 is a graph of the vapor pressure of liquid mixtures of HFC-125and propylene at 25° C.;

FIG. 6 is a graph of the vapor pressure of liquid mixtures of HFC-125and cyclopropane at 0° C.;

FIG. 7 is a graph of the vapor pressure of liquid mixtures of HFC-134and propane at 15° C.;

FIG. 8 is a graph of the vapor pressure of liquid mixtures of HFC-134aand cyclopropane at 0.01° C.;

FIG. 9 is a graph of the vapor pressure of liquid mixtures of HFC-143aand propylene at 25° C.;

FIG. 10 is a graph of the vapor pressure of liquid mixtures of HFC-152aand propane at 25° C.;

FIG. 11 is a graph of the vapor pressure of liquid mixtures of HFC-152aand isobutane at 25° C.;

FIG. 12 is a graph of the vapor pressure of liquid mixtures of HFC-152aand butane at 25° C.;

FIG. 13 is a graph of the vapor pressure of liquid mixtures of HFC-152aand cyclopropane at 25° C.;

FIG. 14 is a graph of the vapor pressure of liquid mixtures of HFC-161and propane at 25° C.;

FIG. 15 is a graph of the vapor pressure of liquid mixtures of HFC-161and cyclopropane at 25° C.;

FIG. 16 is a graph of the vapor pressure of liquid mixtures of HFC-227caand butane at 25° C.;

FIG. 17 is a graph of the vapor pressure of liquid mixtures of HFC-15227ca and cyclopropane at 25° C.;

FIG. 18 is a graph of the vapor pressure of liquid mixtures of HFC-227caand DME at 25° C.;

FIG. 19 is a graph of the vapor pressure of liquid mixtures of HFC-227caand isobutane at 25° C.;

FIG. 20 is a graph of the vapor pressure of liquid mixtures of HFC-227caand propane at 25° C.;

FIG. 21 is a graph of the vapor pressure of liquid mixtures of HFC-227eaand butane at 25° C.;

FIG. 22 is a graph of the vapor pressure of liquid mixtures of HFC-227eaand cyclopropane at 25° C.;

FIG. 23 is a graph of the vapor pressure of liquid mixtures of HFC-227eaand isobutane at 25° C.; and

FIG. 24 is a graph of the vapor pressure of liquid mixtures of HFC-227eaand propane at 25° C.

DETAILED DESCRIPTION

The present invention relates to compositions of difluoromethane(HFC-32) and isobutane, butane, propylene or cyclopropane;pentafluoroethane (HFC-125) and propylene and cyclopropane;1,1,2,2-tetrafluoroethane (HFC-134) and propane;1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane;1,1,1-trifluoroethane (HFC-143a) and dimethyl ether (DME) or propylene;1,1-difluoroethane (HFC-152a) and propane, isobutane, butane andcyclopropane; fluoroethane (HFC-161) and propane or cyclopropane;1,1,1,2,2,3,3-heptafluoropropane (HFC-227ca) and butane, cyclopropane,DME, isobutane or propane; or 1,1,1,2,3,3,3-heptafluoropropane(HFC-227ea) and butane, cyclopropane, isobutane or propane.

The present invention also relates to the discovery of azeotropic orazeotrope-like compositions of effective amounts of difluoromethane(HFC-32) and isobutane, butane, propylene or cyclopropane;pentafluoroethane (HFC-125) and propylene or cyclopropane;1,1,2,2-tetrafluoroethane (HFC-134) and propane;1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane;1,1,1-trifluoroethane (HFC-143a) propylene; 1,1-difluoroethane (HFC-152aand propane, isobutane, butane and cyclopropane; fluoroethane (HFC-161)and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane,isobutane or propane to form an azeotropic or azeotrope-likecomposition.

By "azeotropic" composition is meant a constant boiling liquid admixtureof two or more substances that behaves as a single substance. One way tocharacterize an azeotropic composition is that the vapor produced bypartial evaporation or distillation of the liquid has the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without compositional change.Constant boiling compositions are characterized as azeotropic becausethey exhibit either a maximum or minimum boiling point, as compared withthat of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, orsubstantially constant boiling, liquid admixture of two or moresubstances that behaves as a single substance. One way to characterizean azeotrope-like composition is that the vapor produced by partialevaporation or distillation of the liquid has substantially the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without substantial compositionchange.

It is recognized in the art that a composition is azeotrope-like if,after 50 weight percent of the composition is removed such as byevaporation or boiling off, the difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed is about 10 percentor less, when measured in absolute units. By absolute units, it is meantmeasurements of pressure and, for example, psia, atmospheres, bars,torr, dynes per square centimeter, millimeters of mercury, inches ofwater and other equivalent terms well known in the art. If an azeotropeis present, there is no difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed.

Therefore, included in this invention are compositions of effectiveamounts of difluoromethane (HFC-32) and isobutane, butane, propylene orcyclopropane; pentafluoroethane (HFC-125) and propylene or cyclopropane;1,1,2,2-tetrafluoroethane (HFC-134) and propane;1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane;1,1,1-trifluoroethane (HFC-143a) and propylene; 1,1-difluoroethane(HFC-152a) and propane, isobutane, butane and cyclopropane; fluoroethane(HFC-161) and propane or cyclopropane; 1,1,1,2,2,3,3-heptafluoropropane(HFC-227ca) and butane, cyclopropane, DME, isobutane or propane; or1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and butane, cyclopropane,isobutane or propane such that after 50 weight percent of an originalcomposition is evaporated or boiled off to produce a remainingcomposition, the difference in the vapor pressure between the originalcomposition and the remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range ofcompositions around the azeotrope that, for a maximum boiling azeotrope,have boiling points at a particular pressure higher than the purecomponents of the composition at that pressure and have vapor pressureslower at a particular temperature than the pure components of thecomposition at that temperature, and that, for a minimum boilingazeotrope, have boiling points at a particular pressure lower than thepure components of the composition at that pressure and have vaporpressures higher at a particular temperature than the pure components ofthe composition at that temperature. Boiling temperatures and vaporpressures above or below that of the pure components are caused byunexpected intermolecular forces between and among the molecules of thecompositions, which can be a combination of repulsive and attractiveforces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling pointat a particular pressure, or a maximum or minimum vapor pressure at aparticular temperature, may or may not be coextensive with the range ofcompositions that are substantially constant boiling. In those caseswhere the range of compositions that have maximum or minimum boilingtemperatures at a particular pressure, or maximum or minimum vaporpressures at a particular temperature, are broader than the range ofcompositions that are substantially constant boiling according to thechange in vapor pressure of the composition when 50 weight percent isevaporated, the unexpected intermolecular forces are nonethelessbelieved important in that the refrigerant compositions having thoseforces that are not substantially constant boiling may exhibitunexpected increases in the capacity or efficiency versus the componentsof the refrigerant composition.

The components of the compositions of this invention have the followingvapor pressures at 25° C.

    ______________________________________                                        COMPONENTS        PSIA   KPA                                                  ______________________________________                                        HFC-32            246.7  1701                                                 HFC-125           199.1  1373                                                 HFC-134           76.1   525                                                  HFC-134a          98.3   677                                                  HFC-143a          180.6  1245                                                 HFC-152a          85.8   591                                                  HFC-161           130.2  898                                                  HFC-227ca         63.8   440                                                  HFC-227ea         66.6   459                                                  butane            35.2   243                                                  cyclopropane      105.0  724                                                  DME               85.7   591                                                  isobutane         50.5   348                                                  propane           137.8  950                                                  propylene         165.9  1144                                                 ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-likecompositions of this invention comprise the following (all compositionsare measured at 25° C.):______________________________________ WEIGHTRANGES PREPERREDCOMPONENTS (wt. %/wt %) (wt. %/wt.%)______________________________________HFC-32/isobutane 61-99/1-3970-99/1-30HFC-32/butane 65-99/1-35 70-99/1-30HFC-32/propylene 26-99/1-7470-99/1-30HFC-32/cyclopropane 54-99/1-46 54-99/1-46HFC-125/propylene1-99/1-99 60-99/1-40HFC-125/cyclopropane 66-99/1-3466-99/1-34HFC-134/propane 1-75/25-99 30-75/25-70HFC-134a/cyclopropane1-99/1-99 50-99/1-50HFC-143a/propylene 1-99/1-9970-99/1-30HFC-152a/propane 1-78/22-99 30-78/22-70HFC-152a/isobutane44-99/1-56 60-99/1-40HFC-152a/butane 54-99/1-4670-99/1-30HFC-152a/cyclopropane 1-99/1-99 20-99/1-80HFC-161/propane1-99/1-99 20-99/1-80HFC-161/cyclopropane 1-99/1-9940-99/1-60HFC-227ca/butane 61-99/1-39 70-99/1-30HFC-227ca/cyclopropane27-82/18-73 40-82/18-60HFC-227ca/DME 1-92/8-9960-92/8-40HFC-227ca/isobutane 53-92/8-47 60-92/8-40HFC-227ca/propane1-79/21-99 30-79/21-7OHFC-227ea/butane 61-99/1-3970-99/1-30HFC-227ea/cyclopropane 24-83/17-7640-83/17-6OHFC-227ea/isobutane 52-99/1-48 60-99/1-40HFC-227ea/propane1-79/21-99 40-79/21-60______________________________________

For purposes of this invention, "effective amount" is defined as theamount of each component of the inventive compositions which, whencombined, results in the formation of an azeotropic or azeotrope-likecomposition. This definition includes the amounts of each component,which amounts may vary depending on the pressure applied to thecomposition so long as the azeotropic or azeotrope-like compositionscontinue to exist at the different pressures, but with possibledifferent boiling points.

Therefore, effective amount includes the amounts, such as may beexpressed in weight percentages, of each component of the compositionsof the instant invention which form azeotropic or azeotrope-likecompositions at temperatures or pressures other than as describedherein.

For the purposes of this discussion, azeotropic or constant-boiling isintended to mean also essentially azeotropic or essentially-constantboiling. In other words, included within the meaning of these terms arenot only the true azeotropes described above, but also othercompositions containing the same components in different proportions,which are true azeotropes at other temperatures and pressures, as wellas those equivalent compositions which are part of the same azeotropicsystem and are azeotrope-like in their properties. As is well recognizedin this art, there is a range of compositions which contain the samecomponents as the azeotrope, which will not only exhibit essentiallyequivalent properties for refrigeration and other applications, butwhich will also exhibit essentially equivalent properties to the trueazeotropic composition in terms of constant boiling characteristics ortendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixturewhich may appear under many guises, depending upon the conditionschosen, by any of several criteria:

The composition can be defined as an azeotrope of A, B, C (and D . . . )since the very term "azeotrope" is at once both definitive andlimitative, and requires that effective amounts of A, B, C (and D . . .) for this unique composition of matter which is a constant boilingcomposition.

It is well known by those skilled in the art, that, at differentpressures, the composition of a given azeotrope will vary at least tosome degree, and changes in pressure will also change, at least to somedegree, the boiling point temperature. Thus, an azeotrope of A, B, C(and D . . . ) represents a unique type of relationship but with avariable composition which depends on temperature and/or pressure.Therefore, compositional ranges, rather than fixed compositions, areoften used to define azeotropes.

The composition can be defined as a particular weight percentrelationship or mole percent relationship of A, B, C (and D . . . ),while recognizing that such specific values point out only oneparticular relationship and that in actuality, a series of suchrelationships, represented by A, B, C (and D . . . ) actually exist fora given azeotrope, varied by the influence of pressure.

An azeotrope of A, B, C (and D . . . ) can be characterized by definingthe compositions as an azeotrope characterized by a boiling point at agiven pressure, thus giving identifying characteristics without undulylimiting the scope of the invention by a specific numerical composition,which is limited by and is only as accurate as the analytical equipmentavailable.

The azeotrope or azeotrope-like compositions of the present inventioncan be prepared by any convenient method including mixing or combiningthe desired amounts. A preferred method is to weigh the desiredcomponent amounts and thereafter combine them in an appropriatecontainer.

Specific examples illustrating the invention are given below. Unlessotherwise stated therein, all percentages are by weight. It is to beunderstood that these examples are merely illustrative and in no way areto be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following composition is azeotropic. Thetemperature is 25° C.

    ______________________________________                                                                     Vapor Press.                                     Composition     Weight Percents                                                                            psia   kPa                                       ______________________________________                                        HFC-32/isobutane                                                                              93.8/6.2     249.6  1721                                      HFC-32/butane   99.0/1.0     246.8  1702                                      HFC-32/propylene                                                                              81.0/19.0    261.5  1803                                      HFC-32/cyclopropane                                                                           85.2/14.8    260.6  1797                                      HFC-125/propylene                                                                             79.5/20.5    229.1  1580                                      HFC-125/cyclopropane                                                                          91.3/8.7     209.6  1445                                      HFC-134/propane 52.3/47.7    1643   1132                                      HFC-134a/cyclopropane                                                                         65.5/34.5    137.5  948                                       HFC-143a/propylene                                                                            89.6/10.4    181.2  1249                                      HFC-152a/propane                                                                              45.9/54.1    155.1  1069                                      HFC-152a/isobutane                                                                            75.5/24.5    97.0   669                                       HFC-152a/butane 85.0/15.0    90.5   624                                       HFC-152a/cyclopropane                                                                         44.3/55.7    117.8  812                                       HFC-161/propane 44.5/55.5    161.2  1111                                      HFC-161/cyclopropane                                                                          63.4/36.6    140.8  971                                       HFC-227ca/butane                                                                              84.4/15.6    77.5   534                                       HFC-227ca/cyclopropane                                                                        55.8/44.2    126.5  872                                       HFC-227ca/DME   75.6/24.4    101.0  696                                       HFC-227ca/isobutane                                                                           76.8/23.2    90.0   621                                       HFC-227ca/propane                                                                             51.6/48.4    159.8  1102                                      HFC-227ea/butane                                                                              85.8/14.2    76.8   530                                       HFC-227ea/cyclopropane                                                                        55.2/44.8    125.1  863                                       HFC-227ea/isobutane                                                                           77.6/22.4    88.8   612                                       HFC-227ea/propane                                                                             50.4/49.6    157.4  1085                                      ______________________________________                                    

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial liquid composition at 25° C. Theliquid, and the vapor above the liquid, are allowed to come toequilibrium, and the vapor pressure in the vessel is measured. Vapor isallowed to leak from the vessel, while the temperature is held constantat 25° C., until 50 weight percent of the initial charge is removed, atwhich time the vapor pressure of the composition remaining in the vesselis measured. The results are summarized below.

    ______________________________________                                                     0 wt %    50 wt %                                                Refrigerant  evaporated                                                                              evaporated 0% change in                                Composition  psia   kPa    psia  kPa  vapor pressure                          ______________________________________                                        HFC-32/isobutane                                                              93.8/6.2     249.6  1721   249.6 1721 0.0                                     99/1         247.8  1709   247.5 1706 0.1                                     70/30        240.8  1660   230.3 1588 4.4                                     60/40        234.8  1619   209.6 1445 10.7                                    61/39        235.5  1624   212.3 1464 9.9                                     HFC-32/butane                                                                 99.0/1.0     246.8  1702   246.8 1702 0.0                                     70/30        232.3  1602   217.4 1499 6.4                                     65/35        229.1  1580   206.6 1424 9.8                                     HFC-32/propylene                                                              81.0/19.0    261.5  1803   261.5 1803 0.0                                     99/1         248.8  1715   248.0 1710 0.3                                     70/30        259.3  1788   257.7 1777 0.6                                     60/40        254.3  1753   248.8 1715 2.2                                     50/50        246.7  1701   235.7 1625 4.5                                     40/60        236.6  1631   219.6 1514 7.2                                     30/70        223.8  1543   202.6 1397 9.5                                     29/71        222.3  1533   200.9 1385 9.6                                     27/73        219.3  1512   197.6 1362 9.9                                     26/74        217.8  1502   196.0 1351 10.0                                    HFC-32/cyclopropane                                                           85.2/14.8    260.6  1797   260.6 1797 0.0                                     99/1         249.3  1719   248.2 1711 0.4                                     60/40        250.5  1727   236.5 1631 5.6                                     54/46        246.0  1696   222.5 1534 9.6                                     53/47        245.2  1691   219.7 1515 10.4                                    HFC-125/propylene                                                             79.5/20.5    229.1  1580   229.1 1580 0.0                                     90/10        224.8  1550   222.4 1533 1.1                                     99/1         203.9  1406   201.8 1391 1.0                                     70/30        227.4  1568   225.9 1558 0.7                                     50/50        217.2  1498   206.5 1424 4.9                                     40/60        209.9  1447   194.1 1338 7.5                                     30/70        201.2  1387   183.1 1262 9.0                                     20/80        191.1  1318   174.8 1205 8.5                                     10/90        179.3  1236   169.3 1167 5.6                                     1/99         167.4  1154   166.2 1146 0.7                                     HFC-125/cyclopropane                                                          91.3/8.7     209.6  1445   209.6 1445 0.0                                     99/1         202.2  1394   201.3 1388 0.4                                     66/34        194.9  1344   176.5 1217 9.4                                     65/35        194.1  1338   174.2 1201 10.3                                    HFC-134/propane                                                               90/10        140.0  965    83.6  576  40.3                                    75.6/24.4    158.9  1095   143.0 986  10.0                                    52.3/47.7    164.3  1132   164.3 1132 0.0                                     25/75        157.3  1085   152.1 1049 3.3                                     1/99         138.5  955    137.8 950  0.5                                     HFC-134a/cyclopropane                                                         65.5/34.5    137.5  948    137.5 948  0.0                                     90/10        126.8  874    116.8 805  7.9                                     95/5         117.1  807    106.2 732  9.3                                     99/1         103.2  712    99.5  686  3.6                                     30/70        129.4  892    119.4 823  7.7                                     15/85        120.2  829    109.5 755  8.9                                     10/90        115.9  799    107.5 741  7.2                                     1/99         106.3  733    105.2 725  1.0                                     HFC-143a/propylene                                                            89.6/10.4    181.2  1249   181.2 1249 0.0                                     99/1         180.7  1246   180.7 1246 0.0                                     60/40        178.4  1230   178.1 1228 0.2                                     40/60        174.7  1205   174.2 1201 0.3                                     20/80        170.5  1176   170.0 1172 0.3                                     1/99         166.2  1146   166.1 1145 0.1                                     HFC-152a/propane                                                              45.9/54.1    155.1  1069   155.1 1069 0.0                                     60/40        153.7  1060   152.2 1049 1.0                                     70/30        151.0  1041   146.1 1007 3.2                                     78/22        147.5  1017   134.5 927  8.8                                     79/21        147.0  1014   131.9 909  10.3                                    30/70        153.2  1056   152.0 1048 0.8                                     20/80        149.9  1034   147.6 1018 1.5                                     10/90        144.8  998    142.6 983  1.5                                     1/99         138.6  956    138.2 953  0.3                                     HFC-152a/Isobutane                                                            75.5/24.5    97.0   669    97.0  669  0.0                                     90/10        94.7   653    92.5  638  2.3                                     99/1         87.3   602    86.3  595  1.1                                     60/40        95.7   660    93.9  647  1.9                                     40/60        90.4   623    79.2  546  12.4                                    43/57        91.5   631    82.3  567  10.1                                    44/56        91.8   633    83.3  574  9.3                                     HFC-152a/butane                                                               85.0/15.0    90.5   624    90.5  624  0.0                                     95/5         88.9   613    88.2  608  0.8                                     99/1         86.6   597    86.2  594  0.5                                     70/30        89.0   614    87.4  603  1.8                                     60/40        87.1   601    82.4  568  5.4                                     53/47        85.3   588    76.7  529  10.1                                    54/46        85.6   590    77.6  535  9.3                                     HFC-152a/cyclopropane                                                         44.3/55.7    117.8  812    117.8 812  0.0                                     70/30        113.8  785    110.9 765  2.5                                     90/10        100.4  692    94.3  650  6.1                                     99/1         87.6   604    86.5  596  1.3                                     20/80        114.6  790    113.0 779  1.4                                     1/99         105.8  729    105.4 727  0.4                                     HFC-161/propane                                                               44.5/55.5    161.2  1111   161.2 1111 0.0                                     70/30        156.0  1076   153.2 1056 1.8                                     90/10        142.2  980    137.9 951  3.0                                     99/1         131.6  907    130.9 903  0.5                                     20/80        156.0  1076   153.2 1056 1.8                                     1/99         139.3  960    138.5 955  0.6                                     HFC-161/cyclopropane                                                          63.4/36.6    140.8  971    140.8 971  0.0                                     80/20        138.9  958    138.4 954  0.4                                     99/1         130.8  902    130.7 901  0.1                                     30/70        134.2  925    129.8 895  3.3                                     15/85        125.2  863    116.3 802  7.1                                     10/90        120.4  830    111.6 769  7.3                                     1/99         107.1  738    105.5 727  1.5                                     HFC-227ca/butane                                                              84.4/15.6    77.5   534    77.5  534  0.0                                     92/8         76.4   527    74.5  514  2.5                                     99/1         67.3   464    64.8  447  3.7                                     60/40        75.4   520    67.8  467  10.1                                    61/39        75.5   521    69.0  476  8.6                                     HFC-227ca/cyclopropane                                                        55.8/44.2    126.5  872    126.5 872  0.0                                     80/20        121.4  837    112.6 776  7.2                                     85/15        117.0  807    102.1 704  12.7                                    83/17        119.1  821    106.8 736  10.3                                    82/18        119.9  827    108.9 751  9.2                                     30/70        124.8  860    116.5 803  6.7                                     25/75        123.9  854    110.4 761  10.9                                    26/74        124.1  856    111.5 769  10.2                                    27/73        124.3  857    112.7 777  9.3                                     HFC-227ca/DME                                                                 75.6/24.4    101.0  696    101.0 696  0.0                                     90/10        98.1   676    94.3  650  3.9                                     92/8         96.9   668    90.0  621  7.1                                     93/7         96.1   663    86.1  594  10.4                                    40/60        95.1   656    92.7  639  2.5                                     20/80        90.3   623    88.5  610  2.1                                     1/99         85.9   592    85.8  592  0.1                                     HFC-227ca/isobutane                                                           76.8/23.2    90.0   621    90.0  621  0.0                                     90/10        87.5   603    81.8  564  6.5                                     95/5         82.0   565    70.6  487  13.9                                    93/7         85.0   586    75.3  519  11.4                                    92/8         86.0   593    77.6  535  9.8                                     50/50        88.0   607    75.2  518  14.5                                    55/45        88.6   611    83.0  572  6.3                                     53/47        88.4   610    80.5  555  8.9                                     52/48        88.3   609    79.0  545  10.5                                    HFC-227ca/propane                                                             51.6/48.4    159.8  1102   159.8 1102 0.0                                     30/70        157.9  1089   152.1 1049 3.7                                     20/80        155.0  1069   143.8 991  7.2                                     15/85        152.6  1052   140.9 971  7.7                                     10/90        149.3  1029   139.2 960  6.8                                     1/99         139.4  961    137.9 951  1.1                                     80/20        153.6  1059   136.8 943  10.9                                    78/22        154.9  1068   142.2 980  8.2                                     79/21        154.3  1064   139.7 963  9.5                                     HFC-227ea/butane                                                              85.8/14.2    76.8   530    76.8  530  0.0                                     92/8         76.0   524    75.1  518  1.2                                     99/1         69.0   476    67.7  467  1.9                                     60/40        73.8   509    66.1  456  10.4                                    61/39        74.0   510    67.2  463  9.2                                     HFC-227ea/cyclopropane                                                        55.2/44.8    125.1  863    125.1 863  0.0                                     80/20        119.7  825    111.8 771  6.6                                     90/10        107.4  741    89.5  617  16.7                                    85/15        115.2  794    102.3 705  11.2                                    83/17        117.3  809    106.5 734  9.2                                     84/16        116.3  802    104.5 721  10.1                                    30/70        123.3  850    116.7 805  5.4                                     25/75        122.4  844    111.5 769  8.9                                     23/77        122.0  841    109.7 756  10.1                                    24/76        122.2  843    110.6 763  9.5                                     HFC-227ea/isobutane                                                           77.6/22.4    88.8   612    88.8  612  0.0                                     85/15        88.2   608    87.1  601  1.2                                     99/1         71.0   490    67.6  466  4.8                                     50/50        86.3   595    74.9  516  13.2                                    55/45        87.0   600    81.5  562  6.3                                     53/47        86.8   598    79.4  547  8.5                                     52/48        86.6   597    78.1  538  9.8                                     HFC-227ea/propane                                                             50.4/49.6    157.4  1085   157.4 1085 0.0                                     70/30        155.2  1070   150.8 1040 2.8                                     90/10        133.7  922    91.5  631  31.6                                    80/20        150.0  1034   133.6 921  10.9                                    79/21        150.8  1040   136.3 940  9.6                                     30/70        155.7  1074   151.4 1044 2.8                                     20/80        153.0  1055   144.3 995  5.7                                     10/90        147.8  1019   139.6 963  5.5                                     1/99         139.1  959    137.9 951  0.9                                     ______________________________________                                    

The results of this Example show that these compositions are azeotropicor azeotrope-like because when 50 wt. % of an original composition isremoved, the vapor pressure of the remaining composition is within about10% of the vapor pressure of the original composition, at a temperatureof 25° C.

EXAMPLE 3 Impact of Vapor Leakage at 0° C.

A leak test is perfromed on compositions of HFC-32 and cyclopropane, atthe temperature of 0° C. The results are summarized below.

    ______________________________________                                                     0 wt %    50 wt %                                                Refrigerant  evaporated                                                                              evaporated                                                                              0% change in                                 Composition psia    kpa    psia kPa  vapor pressure                           ______________________________________                                        HFC-32/cyclopropane                                                           83.7/16.3   126.6   873    126.6                                                                              873  0.0                                      99/1        119.7   825    118.9                                                                              820  0.7                                      60/40       122.5   845    116.4                                                                              803  5.0                                      53/47       120.2   829    108.5                                                                              748  9.7                                      52/48       119.8   826    107.1                                                                              738  10.6                                     ______________________________________                                    

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants in anideal vapor compression cycle. The data are based on the followingconditions.

    ______________________________________                                        Evaporator temperature                                                                            48.0° F. (8.9° C.)                          Condenser temperature                                                                             115.0° F. (46.1° C.)                        Liquid subcooled to 120° F. (6.7° C.)                           Return Gas          65° F. (18.3° C.)                           Compressor efficiency is 75%.                                                 ______________________________________                                    

The refrigeration capacity is based on a compressor with a fixeddisplacement of 35 cubic feet per minute and 75% volumetric efficiency.Capacity is intended to mean the change in enthalpy of the refrigerantin the evaporator per pound of refrigerant circulated, i.e. the heatremoved by the refrigerant in the evaporator per time. Coefficient ofperformance (COP) is intended to mean the ratio of the capacity tocompressor work. It is a measure of refrigerant energy efficiency.

    __________________________________________________________________________               Evap. Cond.            Capacity                                    Refrig.    Press.                                                                              Press.                                                                              Comp. Dis. BTU/min                                     Comp.      Psia                                                                             kPa                                                                              Psia                                                                             kPa                                                                              Temp. °F.                                                                   °C.                                                                       COP                                                                              kw                                          __________________________________________________________________________    HFC-32/isobutane                                                              1.0/99.0   32 221                                                                              93 641                                                                              135  57 4.91                                                                             148                                                                              2.6                                      93.8/6.2   154                                                                              1062                                                                             409                                                                              2820                                                                             205  96 4.32                                                                             605                                                                              10.7                                     99.0/1.0   155                                                                              1069                                                                             416                                                                              2868                                                                             214  101                                                                              4.33                                                                             623                                                                              11.0                                     HFC-32/butane                                                                 1.0/99.0   22 152                                                                              68 469                                                                              137  58 5.03                                                                             110                                                                              1.9                                      99.0/1.0   154                                                                              1062                                                                             413                                                                              2848                                                                             214  101                                                                              434                                                                              621                                                                              10.9                                     HFC-32/propylene                                                              1.0/99.0   110                                                                              758                                                                              276                                                                              1903                                                                             162  72 4.50                                                                             403                                                                              7.1                                      81.0/19.0  163                                                                              1124                                                                             422                                                                              2910                                                                             197  92 4.25                                                                             609                                                                              10.7                                     99.0/1.0   156                                                                              1076                                                                             418                                                                              2882                                                                             215  102                                                                              4.32                                                                             626                                                                              11.0                                     HFC-32/cyclopropane                                                           1/99       68 469                                                                              183                                                                              1262                                                                             175  79 4.89                                                                             299                                                                              5.3                                      852/14.8   163                                                                              1124                                                                             425                                                                              2930                                                                             203  95 4.28                                                                             622                                                                              11.0                                     99/1       156                                                                              1076                                                                             419                                                                              2889                                                                             215  102                                                                              432                                                                              628                                                                              11.1                                     HFC-125/propylene                                                             1.0/99.0   109                                                                              752                                                                              275                                                                              1896                                                                             161  72 4.49                                                                             400                                                                              7.0                                      79.5/20.5  124                                                                              855                                                                              318                                                                              2193                                                                             149  65 4.12                                                                             413                                                                              7.3                                      99.0/1.0   128                                                                              883                                                                              337                                                                              2324                                                                             144  62 3.84                                                                             401                                                                              7.1                                      HFC-125/cyclopropane                                                          1/99       67 462                                                                              180                                                                              1241                                                                             175  79 4.85                                                                             293                                                                              5.2                                      91.3/8.7   133                                                                              917                                                                              343                                                                              2365                                                                             147  64 3.92                                                                             421                                                                              7.4                                      99/1       129                                                                              889                                                                              340                                                                              2344                                                                             144  62 3.83                                                                             402                                                                              7.1                                      HFC-134/propane                                                               1.0/99.0   90 621                                                                              232                                                                              1586                                                                             150  66 4.52                                                                             336                                                                              5.9                                      52.3/47.7  107                                                                              738                                                                              270                                                                              1862                                                                             148  64 4.37                                                                             375                                                                              6.6                                      99.0/1.0   50 345                                                                              149                                                                              1020                                                                             150  66 5.04                                                                             243                                                                              4.3                                      HFC-134a/cyclopropane                                                         1/99       66 455                                                                              180                                                                              1241                                                                             175  79 4.85                                                                             292                                                                              5.1                                      65.5/34.5  86 593                                                                              229                                                                              1579                                                                             159  71 4.61                                                                             344                                                                              6.1                                      99/1       60 414                                                                              177                                                                              1220                                                                             151  66 4.69                                                                             269                                                                              4.7                                      HFC-143a/DME                                                                  1.0/99.0   52 357                                                                              150                                                                              1034                                                                             168  75 4.91                                                                             243                                                                              4.3                                      90.9/9.1   116                                                                              801                                                                              302                                                                              2084                                                                             183  84 4.29                                                                             429                                                                              7.6                                      99.0/1.0   118                                                                              813                                                                              322                                                                              2221                                                                             194  90 3.93                                                                             422                                                                              7.4                                      HFC-143a/propylene                                                            1.0/99.0   109                                                                              752                                                                              274                                                                              1889                                                                             161  72 4.50                                                                             400                                                                              7.0                                      89.6/10.4  115                                                                              793                                                                              298                                                                              2055                                                                             155  68 4.28                                                                             408                                                                              7.2                                      99.0/1.0   115                                                                              793                                                                              301                                                                              2075                                                                             155  68 4.24                                                                             406                                                                              7.1                                      HFC-152a/propane                                                              1.0/99.0   89 614                                                                              229                                                                              1579                                                                             150  66 4.54                                                                             333                                                                              5.9                                      45.9/54.1  79 545                                                                              211                                                                              1455                                                                             156  69 4.63                                                                             317                                                                              5.6                                      99.0/1.0   52 359                                                                              156                                                                              1076                                                                             168  76 4.82                                                                             248                                                                              4.4                                      HFC-152a/isobutane                                                            1.0/99.0   31 214                                                                              91 627                                                                              135  57 4.78                                                                             139                                                                              2.4                                      75.5/24.5  49 338                                                                              142                                                                              979                                                                              156  69 4.80                                                                             222                                                                              3.9                                      99.0/1.0   52 359                                                                              154                                                                              1062                                                                             167  75 4.81                                                                             245                                                                              4.3                                      HFC-152a/butane                                                               1.0/99.0   21 145                                                                              65 448                                                                              138  59 4.89                                                                             103                                                                              1.8                                      85.0/15.0  45 310                                                                              135                                                                              931                                                                              162  72 4.87                                                                             215                                                                              3.8                                      99.0/1.0   51 352                                                                              153                                                                              1055                                                                             168  76 4.82                                                                             243                                                                              4.3                                      HFC-152a/cyclopropane                                                         1.0/99.0   66 455                                                                              179                                                                              1234                                                                             175  79 4.84                                                                             290                                                                              5.1                                      44.3/55.7  60 414                                                                              169                                                                              1165                                                                             173  78 4.83                                                                             272                                                                              4.8                                      99.0/1.0   52 359                                                                              155                                                                              1069                                                                             168  76 4.82                                                                             246                                                                              4.3                                      HFC-161/propane                                                               1.0/99.0   90 621                                                                              229                                                                              1579                                                                             150  66 4.53                                                                             334                                                                              5.9                                      44.5/55.5  94 648                                                                              244                                                                              1682                                                                             159  71 4.56                                                                             361                                                                              6.4                                      99.0/1.0   83 572                                                                              229                                                                              1579                                                                             175  79 4.69                                                                             356                                                                              6.3                                      HFC-161/cyclopropane                                                          1.0/99.0   66 455                                                                              178                                                                              1227                                                                             174  79 4.87                                                                             289                                                                              5.1                                      63.4/36.6  75 517                                                                              206                                                                              1420                                                                             174  79 4.79                                                                             328                                                                              5.8                                      99.0/1.0   84 579                                                                              230                                                                              1586                                                                             174  79 4.70                                                                             357                                                                              6.3                                      HFC-227ca/butane                                                              1.0/99.0   21 145                                                                              65 448                                                                              137  58 4.89                                                                             103                                                                              1.8                                      84.4/15.6  34 234                                                                              103                                                                              710                                                                              129  54 4.61                                                                             149                                                                              2.6                                      99.0/1.0   38 262                                                                              115                                                                              793                                                                              127  53 4.45                                                                             160                                                                              2.8                                      HFC-227ca/cyclopropane                                                        1.0/99.0   66 455                                                                              177                                                                              1220                                                                             174  79 4.88                                                                             289                                                                              5.1                                      55.8/44.2  76 524                                                                              202                                                                              1393                                                                             154  68 4.65                                                                             303                                                                              5.3                                      99.0/1.0   40 276                                                                              124                                                                              855                                                                              130  54 4.24                                                                             164                                                                              2.9                                      HFC-227ca/DME                                                                 1.0/99.0   52 359                                                                              149                                                                              1027                                                                             167  75 4.90                                                                             242                                                                              4.3                                      75.6/24.4  66 455                                                                              184                                                                              1267                                                                             142  61 4.48                                                                             260                                                                              4.6                                      99.0/1.0   41 283                                                                              122                                                                              841                                                                              128  53 4.49                                                                             170                                                                              3.0                                      HFC-227ca/isobutane                                                           1.0/99.0   31 214                                                                              90 621                                                                              135  57 4.79                                                                             138                                                                              2.4                                      76.8/23.2  36 248                                                                              106                                                                              731                                                                              130  54 4.61                                                                             155                                                                              2.7                                      99.0/1.0   38 262                                                                              115                                                                              793                                                                              127  53 4.45                                                                             160                                                                              2.8                                      HFC-227ca/propane                                                             1.0/99.0   88 607                                                                              226                                                                              1558                                                                             145  63 4.53                                                                             326                                                                              5.7                                      51.6/48.4  76 524                                                                              205                                                                              1413                                                                             141  61 4.46                                                                             288                                                                              5.1                                      99.0/1.0   40 276                                                                              120                                                                              827                                                                              127  53 4.47                                                                             167                                                                              2.9                                      HFC-227ea/butane                                                              1.0/99.0   21 145                                                                              65 448                                                                              137  58 4.90                                                                             103                                                                              1.8                                      85.8/14.2  34 234                                                                              102                                                                              703                                                                              129  54 4.60                                                                             148                                                                              2.6                                      99.0/1.0   37 255                                                                              113                                                                              779                                                                              127  53 4.46                                                                             157                                                                              2.8                                      HFC-227ea/cyclopropane                                                        1.0/99.0   66 455                                                                              179                                                                              1234                                                                             175  79 4.85                                                                             291                                                                              5.1                                      55.2/44.8  75 517                                                                              201                                                                              1386                                                                             154  68 4.61                                                                             300                                                                              5.3                                      99.0/1.0   42 290                                                                              125                                                                              862                                                                              128  53 4.45                                                                             173                                                                              3.0                                      HFC-227ea/isobutane                                                           1.0/99.0   31 214                                                                              89 614                                                                              135  57 4.79                                                                             138                                                                              2.4                                      77.6/22.4  36 248                                                                              105                                                                              724                                                                              130  54 4.60                                                                             153                                                                              2.7                                      99.0/1.0   38 262                                                                              113                                                                              779                                                                              127  53 4.46                                                                             157                                                                              2.8                                      HFC-227ea/propane                                                             1.0/99.0   88 607                                                                              226                                                                              1558                                                                             145  63 4.53                                                                             326                                                                              5.7                                      50.4/49.6  76 524                                                                              204                                                                              1407                                                                             141  61 4.47                                                                             288                                                                              5.1                                      99.0/1.0   39 269                                                                              119                                                                              820                                                                              129  54 4.35                                                                             160                                                                              2.8                                      __________________________________________________________________________

EXAMPLE 5

This Example is directed to measurements of the vapor pressure of thefollowing liquid mixtures of this invention at 25° C.: HFC-32/isobutane;HFC-32/butane; HFC-32/propylene; HFC-125/propylene; HFC-143a/propylene;HFC-152a/propane; HFC-152a/isobutane; HFC-152a/butane;HFC-152a/cyclopropane; HFC-161/propane; HFC-161/cyclopropane;HFC-227ca/butane; HFC-227ca/cyclopropane; HFC-227ca/DME;HFC-227ca/isobutane; HFC-227ca/propane; HFC-227ea/butane;HFC-227ea/cyclopropane; HFC-10 227ea/isobutane; and HFC-227ea/propane.The vapor pressures for these mixtures are shown in FIGS. 1-3, 5 and9-24.

The vapor pressure data for the graph in FIG. 1 are obtained as follows.A stainless steel cylinder is evacuated, and a weighed amount of HFC-32is added to the cylinder. The cylinder is cooled to reduce the vaporpressure of HFC-32, and then a weighed amount of isobutane is added tothe cylinder. The cylinder is agitated to mix the HFC-32 and isobutane,and then the cylinder is placed in a constant temperature bath until thetemperature comes to equilibrium, at which time the vapor pressure ofthe HFC-32 and isobutane in the cylinder is measured. This procedure isrepeated at the same temperature with different weight percents of thecomponents, and the results are plotted in FIG. 1.

Data are obtained in the same way for the mixtures plotted in FIGS. 2,3, 5 and 9-24.

The data in FIGS. 1-3, 5 and 9-24 show that at 25° C., there are rangesof compositions that have vapor pressures higher than the vaporpressures of the pure components of the composition at that sametemperature.

EXAMPLE 6

This Example is directed to the measurements of the vapor pressure ofthe following liquid mixtures of this invention: HFC-32/cyclopropane;HFC-125/cyclopropane; HFC-134/propane; and HFC-134a/cyclopropane. Thevapor pressures of these mixtures were measured at particularcompositions as shown by the asterisks in FIGS. 4 and 6-8, and a bestfit curve was drawn through the asterisks.

The procedure for measuring the vapor pressures for mixtures of HFC-32and cyclopropane was as follows. A stainless steel cylinder wasevacuated, and a weighed amount of HFC-32 was added to the cylinder. Thecylinder was cooled to reduce the vapor pressure of HFC-32, and then aweighed amount of cyclopropane was added to the cylinder. The cylinderwas agitated to mix the HFC-32 and cyclopropane, and then the cylinderwas placed in a constant temperature bath until the temperature came toequilibrium at 0° C., at which time the vapor pressure of the content ofthe cylinder was measured. This procedure was repeated for variousmixtures of HFC-32 and cyclopropane as indicated in FIG. 4.

The data in FIG. 4 show that at 0° C., there are ranges of compositionsthat have vapor pressures higher than the vapor pressures of the purecomponents of the composition at that same temperature.

The procedure for measuring the vapor pressure of mixtures ofHFC-32/cyclopropane was carried out in the same way for mixtures ofHFC-125/cyclopropane, HFC-134/propane and HFC-134a/cyclopropane, exceptthat the measurements of the vapor pressure of mixtures ofHFC-134/propane were taken at 15° C. and the measuements of the vaporpressure of mixtures of HFC-134a/cyclopropane were taken at 0.01° C.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling pointof -60° to +60° C., hydrofluorocarbonalkanes having a boiling point of-60° to +60° C., hydrofluoropropanes having a boiling point of between-60° to +60° C., hydrocarbon ethers having a boiling point between -60°to +60° C., hydrochlorofluorocarbons having a boiling point between -60°to +60° C., hydrofluorocarbons having a boiling point of -60° to +60°C., hydrochlorocarbons having a boiling point between -60° to +60° C.,chlorocarbons and perfluorinated compounds, can be added to theazeotropic or azeotrope-like compositions described above.

Additives such as lubricants, surfactants, corrosion inhibitors,stabilizers, dyes and other appropriate materials may be added to thenovel compositions of the invention for a variety of purposes providesthey do not have an adverse influence on the composition for itsintended application. Preferred lubricants include esters having amolecular weight greater than 250.

It is claimed that:
 1. An azeotropic or azeotrope-like compositionconsisting essentially of 1-99 wt % 1,1,1,2-tetrafluoroethane (R 134a)and 1-99% cyclopropane (R 270), wherein said composition has a vaporpressure at 25° C. of about 103.2 psia to about 137.5 psia.
 2. A processfor producing refrigeration, comprising condensing a composition ofclaim 1 and thereafter evaporating said composition in the vicinity ofthe body to be cooled.
 3. A process for producing heat comprisingcondensing a composition of any of claim 1 in the vicinity of a body tobe heated, and thereafter evaporating said composition.